Clegg's comments came as Tim Farron, the party's president, admitted: "We screwed this up", when he was questioned on BBC Radio 4's Today programme about the Liberal Democrats' handling of the issue.

Farron said: "That is something that we have to learn from, apologise for and make sure it never happens again."

The deputy prime minister has faced criticism after Lib Dem officials spent three days insisting he had not known about complaints over the behaviour of the former party chief executive and strategist Lord Rennard, which were made on Channel 4 news on Thursday.

On Sunday, he said that he had been made aware of "indirect and non-specific concerns" in 2008, prompting questions about why he did not launch a full investigation at the time.

But Clegg insisted on Monday he had acted appropriately at the time given the level of information available to him.

"We'll obviously now have to look at this very carefully," he told BBC Radio Solent. "I have got absolutely nothing to hide, why would I? … The problem is … that until last week no very specific allegations were put to me. We acted on general concerns which had been expressed some time ago."

Clegg responded to the "general concerns" by asking Danny Alexander, the then chief of staff and now chief secretary to the Treasury, to talk to Rennard and warn him that such behaviour would be "wholly unacceptable". He said Rennard denied he had behaved inappropriately and continues to do so.

The Lib Dem leader said the women making the allegations against Rennard had at the time wanted to have their names and details protected. "It's only last week that these general concerns evolved into something specific which we can act on and which we will."

He said one of the women had worked in his office and was very close to him but "never said a word to me".

"I can't rewrite history, I wasn't given any specific allegations directly … including from someone who worked with me directly … I have got nothing to hide, the party has nothing to hide," he said.

Clegg said he expected the independent investigation into how the allegations were handled would reveal that "some [party] procedures were flawed". The investigation was to have been led by Farron but after growing criticism the Lib Dem leader said it would be chaired independently.

The party president said: "The one thing I probably can tell you without going through due process is that we screwed this up as a party. There are individuals out there who we had a duty of care towards and we did not fulfil that duty of care. That is something that we have to learn from, apologise for and make sure it never happens again."

Farron said he first heard a "general rumour" about a year ago "but no specifics, not even who or what or when or anything. In my job you come across quite a lot of gossip and it is difficult to know how you separate out general unspecific gossip from specific complaints. That is why we, as a party, with independent help and with real rigour, are now going to look at ourselves."